What is a good analogy that clarifies the function of the lysosomes in a cell?

Answer

The best analogy for lysosomes functioning in a cell is a vulture surveying its territory for weak and dying animals. The primary function of lysosomes is to digest undesirable objects inside the protoplasm of the cell. Ultimately, the lysosomes digest the cell when it dies.

In the wild, vultures fly around looking for food. Rather than try to kill live animals that could fight back and hurt them, they only eat animals that are either dead or very weak. By eating these dead and dying creatures, vultures help to keep the ecosystem clean, harvest the last bit of energy in these dying animals and recycle the constituent parts back into the ecosystem.

Lysosomes work the same way. While they need not fear that their food fights back, they do not want to eat things that are functioning properly still. If a small organelle is working and a lysosome eats it, the cell loses the energy and function of the organelle. By contrast, when the lysosome eats a dead organelle, it helps to keep the cell’s inner world clear from debris. Lysosomes also break down food particles and foreign matter in the cell. In this way, lysosomes provide a janitorial service for the cell.